Walter r



Patented Aug. 5, 1930 UNITED STATES PATENT OFFICE WALTER B. UAPP, OF. SYRACUSE, NEW YORK, ASSIGN OR TO SEMET-SOLVAY COM- PANY, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK DILUTING COKE-OVEN GAS WITH FL'UE GAS 1 Ho Drawing.

The present invention relates to a gas mixture comprising a diluted coke oven gas and the method of preparing the same.

.Coke oven gas, the regular product of 5 standard by-product coke oven practice, has a calorific value which in many cases and for many uses is in excess of the B. t. u. requirements or necessities of a given situation. It has consequently been customary in such cases to dilutethe coke oven gas to produce a gas mixture which will correspond with the requirements "relative to a reduced 1 B. t. u. content.

Various expedients have been heretofore employed for diluting coke oven gas in order to reduce the calorific power of the latter to a desired range. Among them was the method of diluting coke oven gas with producer gas or water gas, but this procedure involved the installation of costly apparatus to generate said diluents as well as increased operating costs and operating difiiculties. Another expedient was the use of lime-kiln gas as a diluent. This procedure, however, can only be relied upon where a lime-kiln is located near the coke oven; and even in this situation the diluent gas carries various impurities which are objectionable in the coke oven gas. The method embodying the present invengoing as well as other dificulties. The invention provides a simple and economical method of diluting coke oven gas which is universally applicable wherever a coke oven may be located. 1

A preferred procedure of carrying the present method into practice will be described. This, procedure may be used with any of the standard by-product coke ovens,

all of which have a series of coking chambers,

heating flues interposed between the said chambers and regenerators or recuperators associated with the said heating flues. Air is passed throu h hot re enerators or recuperators and t en the uel-air mixture is permitted to burn in the flues of a coke oven wherein combustion is effected, the heat bein transmitted to the coal located in the eeing chambers. After. the gases have tion was devised in order to obviate the fore- Application filed December 4, 1925. Serial No. 73,262.

passed through the heating flues, the products of combustion are withdrawn to a chimney flue via a regenerator (or recuperator) which extracts heat from the hot waste gases. The heat from the flues drives ofi volatile matter from the, coal or other substance contained in the coking chambers of the oven, This volatile matter is treated to extractpraca tically all of the solids and liquids contained therein. After the said treatment, only a fuel gas or coke oven gas remains which is pumped tov usual gas holders from which the gas is subsequently delivered to the place of it; consumption as a relatively cool stream 0 gas.

According to the present invention the gases which pass through the heating flues are so constituted with respect to their content of fuelv gas and air respectively, and are allowed a suflicient extent of travel in the heating flues of the coke oven, that substantially complete combustion of all of the'oxywill bedevoid of substantial quantities of free oxygen or inert with respect to any trace of oxygen or oxygen combinations capable of supporting combustion which they may retain. A portion of this waste inert gas devoid of relative substantial quantities of free oxygen is withdrawn from the chimney flue and after treatment, if desired, to remove substances such as sulphur dioxide and other sulphur compounds which mi ht be deleterious in subsequent handling ot the inert gas, is mixed with said fuel gas or coke oven gas. By varying'the proportions of this waste inert gas to the fuel gas, the calorific value. of the fuel or coke oven gas as stored in the gas holders may be lowered to any desired predetermined value without any detrimental I oven as may have a calorific value'of from 550 to 600 B. t. u. per cubic foot. By adding approximately 5 to 10% of waste inert gases from the chimney flue to the aforesaid coke oven gas, a desired B. t. u. content in the diluted gas will be obtained, say from about 500 to 525 or 540 B. t. u. per cubic foot. Of

course, the proportion of admixture of the flue gas to the coke oven gas may be regulated so that any desired calorific value in the mixed resultant gas may be obtained.

It will be observed from the foregoing description that a simple unitary process is provided which eliminates all difiiculties connected with auxiliary apparatus, which is practically free from any substantial expense either in installation or operation and which is always available in conjunction with the production of coke oven gas wherever a coke oven is located. It will be observed that they new product as produced in following this invention will be a gas mixture which consists of. a major part of standard. coke oven gas and a minor art of a relatively completely deoxidized burned coke oven flue gas and that such a product can be easily, conveniently,

free oxygen and possessing no calorific value, passing the said waste gas in heat-exchange relation with heat-absorbing elements to extract heat from said waste gas, and after thus reducing the temperature of the waste gas,

mixing regulated quantities thereof at its reduced temperature with the coke oven gas product to produce a mixed gas having a predetermined calorific value which is lower than the calorific value of said coke oven gas.

2. The process of regulating a coke oven gas mixture with respect to the B. t. u. content thereof which comprises evolving vola-' my hand.-

- WALTER R. KNAPP.

and cheaplyprepared by burning fuel gas to complete combustion in the heating flues of a coke oven to cause the evolution of volatile matter from the charge; removing substantially all of the liquid and solid substances from said volatile matter whereby only residual coke oven gas remains, using a portion of said coke oven gas to heat subsequent charges, mixing a portion of the resultant flue gas with the balance of said coke oven gas, and regulating the proportion of the admixture with respect to the desired calorific value of the mixed gas.

I claim:

1. T he process of obtaininga coke oven gas mixture at a predetermined reduced B. t. u

= content which consists in distilling combustible carbonaceous material by the application of heat, collecting the distilled products from the aforesaid step, treating said products to remove liquid and solid substances therefrom so that only residual coke oven gas remains, combustmg a predetermined portion of said coke oven gas for the generation of heat to eifect the distillation of the combustible materlal 1n the first mentioned step and to produce a waste gas containing practically no 

